In chemistry, what does adhesion refer to?

Adhesion refers to the attractive forces between different substances or phases. This concept is crucial in understanding how various materials interact at their interface. For example, when water sticks to the surface of a glass, it is a result of adhesion; the water molecules are attracted to the molecules of the glass. This property is significant in numerous chemical and physical processes, such as capillary action, where liquids rise in narrow spaces due to adhesive forces overcoming gravitational effects.

In contrast, the other options describe different phenomena. The idea of repulsion between similar molecules pertains more to cohesive forces, which is the attraction between like substances. Chemical bond formation relates to the strong interactions that hold atoms together within molecules, which is distinct from the surface interactions described by adhesion. Processes affecting boiling points typically involve intermolecular forces and not the specific interactions between different phases or substances.